I think part of the debate stems from the thought that the moves to create a village will slowly take away the ways our fanbase gathers before games.
Older Bills fans have had a long hard journey over the years and as younger ones join the the force, they bring with them their rituals. To the dismay of the NFL and the Bills, their rituals are displayed on Barstool sports and instagram for all to see. Its not that we are all different, we just celebrate and prepare differently.
To answer the OP,
Being a Bills fan to me is waking up on gameday in December, knowing that the playoff hopes were gone 3 weeks ago, and still hoping for a win, hoping for improvement by the young players and looking forward to a good game and having a few beers with old friends and meeting new ones.
Being a Bills fan is walking down the street in Manhattan and hearing "Go Bills" because you are wearing a Bills hat or shirt.
Being a Bills fan is having Dad put the radio next to the phone in 1983 so I could listen to Van's call as Dad kept shouting "Hey that's long distance, that's going to cost you a fortune"
Being a Bills fan is when on vacation, and the family knows that whatever happens, Sunday at 1 PM, Dad and Mom will be in front of a TV at a sports bar near the beach where the kids can do whatever they want for the next 3 hours.
Being a Bills fan is sitting at that beach bar, chatting with an ex-Buffalo cop talking about how the team is on the right track, and maybe next year we will make a run (and seriously believing it).
Being a Bills fan is setting aside vacation time to make sure you can travel 900 miles round trip for each home game, shorter for some road games. Being a Bills fan is keeping your season tickets since 1982 because you didn't want the team to have another reason to leave.
Being a Bills fan is spending countless hours on internet forums complaining about the latest trade or a misplaced shower mat.